At 99.5 the heart rate is normal. As the temp increases so does the heart rate which explains why chicks are born early in incubators that are running hot.
The heart rate does have a upper limit and when that is reached the heart stops which explains why even a short burst of high temperature can kill all of the eggs.

Now the fun part is that when a egg cools down the heart rate drops to conserve energy. This is useful when the hen leaves the nest.
If a incubator runs low then the chick will be late or non viable as a slower heart rate conserves energy but its still using energy and the egg has a limited amount.
Now it has been tested that you can remove a egg from a incubator and stick it in the fridge until the heart rate reaches 60bpm (they did this for over a hour). If the egg is then placed back in the incubator the heart rate will return as the egg warms back up and the chick will hatch with no ill affects. At around 55bpm the heart rate stops and will not restart.

So during a power outage as the temp drops the heart rate in the egg will slow down and as long as the heat is restored before the egg reaches 60bpm then the egg will still be viable. In a 70 degree home that will take hours for the heart rate to drop into the danger zone. As the incubator will take a while to cool down even long power cuts may have very little affect on the eggs.

im still searching for the report. If I find it I will post it, (read it on my phone which is why I didn't copy the link)

At 99.5 the heart rate is normal. As the temp increases so does the heart rate which explains why chicks are born early in incubators that are running hot.
The heart rate does have a upper limit and when that is reached the heart stops which explains why even a short burst of high temperature can kill all of the eggs.

Now the fun part is that when a egg cools down the heart rate drops to conserve energy. This is useful when the hen leaves the nest.
If a incubator runs low then the chick will be late or non viable as a slower heart rate conserves energy but its still using energy and the egg has a limited amount.
Now it has been tested that you can remove a egg from a incubator and stick it in the fridge until the heart rate reaches 60bpm (they did this for over a hour). If the egg is then placed back in the incubator the heart rate will return as the egg warms back up and the chick will hatch with no ill affects. At around 55bpm the heart rate stops and will not restart.

So during a power outage as the temp drops the heart rate in the egg will slow down and as long as the heat is restored before the egg reaches 60bpm then the egg will still be viable. In a 70 degree home that will take hours for the heart rate to drop into the danger zone. As the incubator will take a while to cool down even long power cuts may have very little affect on the eggs.

im still searching for the report. If I find it I will post it, (read it on my phone which is why I didn't copy the link)

So many reports on this subject and most are above what a normal person would understand. Is there a doctor in the house..lol

well it seems they all agree that the magic number for high temp is 114-115 internal egg temp so if you wake up one morning to find the incubator reading 110 I would say that its worth waiting to see what hatches. If it reads 126 then its probably time to throw a hissy fit and start again.

As for low temp it seems more complicated as its based on age. 40 degrees F for 1 hour internal temp seems to be about the limit after day 8. It also seems that up to around day 12 the heart can be stopped or taken to such a slow rate that it can no longer be detected and once warmed up the heart rate will return. My personal experience seems to contradict this as I have had cockatiel eggs that have been abandoned for less than 24hrs at a average temp in the low 70's and they all died. Of course they could have failed for other reasons which is why the hen abandoned them in the first place (they candled well 4 days earlier and the hen was happy to sit on them for the next 3 days).

In case you are wondering why im researching stuff like this. Im trying to find a way to test dark eggs so im more interested in how the people are recording the heart rate in a non invasive way. They do sell machines to do this but there designed for large hatchery's that can afford thousands of dollars.

I don't think you can compare a cockatiel to a hen. Have you tried a high end stethoscope? I also wonder if you could use the metabolic activity of the developing chick to your advantage. Some incubators come equipped with a cool down phase. Not sure how long that cool down phase is, but if you checked the temp of each egg at the end of the cool down phase, I'm guessing that the viable eggs would remain warmer.

In case you are wondering why im researching stuff like this. Im trying to find a way to test dark eggs so im more interested in how the people are recording the heart rate in a non invasive way.

Click to expand...

An old fashion time proven stethoscope works, you need to get the 'cone' variety used on infants or better yet a neonatal one as the smaller cone shape better seals and conforms to the egg... The common large flat ones that are used on adults won't work right...

An old fashion time proven stethoscope works, you need to get the 'cone' variety used on infants or better yet a neonatal one as the smaller cone shape better seals and conforms to the egg... The common large flat ones that are used on adults won't work right...

Click to expand...

thanks for the info. My plan one day is to have something that I can lay a egg on and get a green light or red light to indicate that the egg is viable. I have never seen a cone style stethoscope so I will have to look for one. With a few mods it might be possible to add a mic and plug it into the sound card on the pc to make a simple test.